Ubuntu 9.04 will represent the next upgrade from either 8.04 Long Term Release (LTR), which is supported through April 2011; or the 8.10 standard release, which is supported through 2010. The OS is available in 32-bit x86 (i386), 64-bit x86 (AMD64) and armel ixp4xx (for ARM-based netbooks and MIDs).
New features include:
1) Gnome 2.26 desktop environment, which includes the following new features:
a) brasero, an all-in-one CD burning application.
b) Improved multi-monitor handling.
2) X.Org server 1.6, which supports several new video cards, as well as ATI-specific performance improvements including EXA acceleration by default, 2D support for R6xx/R7xx, 3D support for R5xx cards, along with an updated -fglrx proprietary driver for R6xx/R7xx 3D support.
3) New notification style and preferences.
4) Boot performance is "significantly improved".
5) Linux kernel 2.6.28-11.37, which is based on 220.127.116.11.
6) Ext4 file system support.
7) Server edition includes support for cloud computing via Eucalyptus, an open source technology which is included in Ubuntu as a technology preview, enables you to use your own servers to deploy, experiment and test your own private cloud that matches the Amazon EC2 API.
8) Turn-key mail servers with the dovecot-postfix package, which supports SMTP, POP3 and IMAP with TLS and SASL.
Any thoughts before the April 23 official release?
Ubuntu runs fine in a VM. So if you want to try out Ubuntu from Windows and don't want to install it on your harddrive just run it inside a VM. If you're happy with that why not migrate and see how well you do. You can still install Virtualbox on Ubuntu and run Windows from there, if you need it.
I've installed it in a VM using VMWare Server 2.0.1. I can't get VMWare Tools to work properly with it though. On installing VMWare Tools and manually starting vmware-user the "seamless" change of control between guest and host works fairly well, but the GUI is still quite laggy. Upon restarting the VM, vmware-user is no longer running, and manually starting it has the same result as earlier. However, I did get multiple errors saying
Unable to locate theme engine in module_path: "murrine"
I don't have much experience with VMware, but Virtualbox worked fine for me on both Windows and Linux and is free of charge. It's also in continuing development, right now they just released version 2.2.2. You may want to try it, it worked fine for me including the seamless integration, without any lag at all when switching.